As a young Augustinian monk on his first trip abroad, Martin Luther was clearly disappointed by Rome, remarking that “if there is a hell then Rome is built on it”. He was never going to be a travel PR for the city. In the 18th century, Goethe was rather more enthusiastic: “Yes, I have finally arrived at the Capital of the World! I now see all the dreams of my youth coming to life,” he wrote. While Luther’s hatred of Rome was intellectual and theological – he described the Church as “the most lawless den of thieves, the most shameless of all brothels” – the feelings of the two Germans in some ways will resonate with most who visit Rome, an exemplary tourist trap perfected over centuries of being one of the world’s paramount destinations. Medieval and Renaissance Holy Years made Rome the birthplace of mass tourism.